Aerial navigation machine utilizing a light gas



M y 1934. E. E. OEHMICHEN 1,957,149

AERIAL NAVIGATION MACHINE UTILIZING A LIGHT GAS Filed March 15, 1932 Patented May 1, 1934 STATES ee ie Etienne Edmond Oehmichen, Valentigney, France Application March 15,

1932, Serial No. 599,038

In France March 1'7, 1931 1 Claim.

I have filed an application in France on March 17th, 1931.

The present invention relates to an aerial navigation machine of special construction and of a combined system, that is to say, that its ascending force is due simultaneously to the aerostatic lift of the air and to the aerodynamic actions of the sustaining propellers. The principles of the present invention, which have been established to a great extent in accordance with the experience and personal experiments of the inventor, are explained hereafter:

An elongated balloon, for example, of only 400 cubic meters has a radius of action of practically zero, for it can hardly carry the weight of one passenger and that of the machine and attain a speed of approximately 50 kilometers per hour.

The said sustaining systems will be capable of developing a carrying capacity, the average of 20 which varies from 6 to '7 kilos per horse power.

The machine in question fitted out with such a sustaining system will therefore be capable of raising an additional load, besides the material already loaded, which additional load may vary from 3 to 6 kilos for each horse power supplied by the sustaining engine. Supposing that the number of horse power of the said engine is P, the machine will then be capable of carrying a load of fuel equal to at least 3 P. Consequently,

the same will have a much larger radius of action. Under these conditions the balloon of 400 cubic metres, which We have considered, supplied with a sustaining system of 40 horse power, will increase its radius of action from 0 to 350 kilometres.

On the other hand it is not necessary to employ a supplementary motor for actuating the sustaining system, but use may be made of the same motor of the flying machine, thus increasing 40 the radius of action in a still more considerable manner.

The sustaining propellers may be of the ordinary type with vertical axes or inclined ones.

On account of the translation the ordinary sustaining propellers will be enabled to increase their sustaining qualities in a very efficient manner. The composing parts will be dimensioned in such a manner that the start with full load does not require the whole power of the motor for the sustentation but on the contrary a porwill be possible to diminish considerably the incidence of the sustaining propellers and consequently to liberate an important quantity of power, which the driving propeller will utilize in an efiicient manner.

The inclined propellers are more advantageous 1 since they permit to obtain horizontal driving efiiciencies which are equal to those supplied by an ordinary propeller disposed in normal manner besides giving the benefit of a very important component of translation.

Under these latter conditions an aerial navigation machine of 400 cubic metres, as considered previously, supplied with sustaining pro+ pellers of about 20 inclination and fitted out with an engine of 4.0 horse power driving the. said propellers and at the same time having a supplementary horizontal driving propeller of variable and reversible pitch, will reach and even surpass a radius of action of 1000 kilometres.

However, it may be mentioned now, that the machine has changed its character entirely'and has become a machine of the heavier-than-air type.

Consequently, if, on account of an accident to the mechanism, the sustaining effort developed mechanically fails, the machine will tend to drop. It is, therefore, indispensable either to avoid this l'all or to reduce the speed of the fall suflici'ently so as to ensure a safe landing without accident. One way, for instance, to reduce the speed'of the fall consists in releasing the machine instantaneously by unloading as rapidly as possible the load of fuel, which is of considerableweight. Further to release all heavy articles, which can be spared without causing inconvenience, should be once it exceeds this limit, even with landing devices of long course, the regaining of contact with the ground will generally damage the machine. If the release is insufiicient to limit the fall to a speed inferior to 5 metres, the machine must moreover be so arranged as to ofier a certain resistance to the air during the said fall.

It is known that the resistance to the advancement of a balloon in the air is generally very weak. This resistance which we shall call longitudinal resistance and which is generally reported to be of a speed of 10 metres per second, is of an-average of 1 50 but may amount to 1/100 of the transversal resistance or the resistance which the envelope oiiers to a translating movement, which takes place at the same speed but in a direction perpendicular to the longitudinal axis of the balloon.

For instance, an elongated balloon of 21 metres in length and of a midship diameter of 6 metres provided with its featherings develops in translation movement perpendicular to its longitudinal axis a resistance of 140 kilos at thespeed of 5 metres per second and by suitable means, such as collars or longitudinal braking surfaces of very.

weak development, this resistance may under the same conditions reach 230 kilos. Thus, in a horizontal projection with equal surface, theremay. be obtained a resistance of equal value with thatof any of the best parachutes.

All these principles being thus established, the

invention has for its objectthe combination of an aerial navigation machine of small volume with a driving machine actuating one or more propellers, which are capable of developing .at the same time sustaining efforts as well as horizontal drivingefforts, the said combination being chiefly characterized as follows: I

The total ascending force, that is to say, the lift of the air on the whole machine, which is not sufficient toraise the machine, is comprised between two limits.

= Thelowerlimit (this lower limit being quite -rig orous in the present case) of the ascending power obaerostatic lift of the air on whole, the machine is equal to the weight of the machine as described previously (envelope, gas, accessories, engine, passengers, armament etc.) not including the fuel'and furthermore diminished-by the transversal-re- :sistance opposed by the machine during a uniform=descent of 5 -metres per second in calm air.

When the ascending forceis in the proximity of the upper-limiter for some important reason surpasses the same and'if the sustaining engine stops, it will be. sufficient .torelease the whole or mportion of the fuel .in order to keep the aerial navigation :machine in the air.

.On"the-1contrary, when the ascending force is close to the lower limit and if the engine stops even "after evacuating all the fuel which isdisposeble, then the descent will obviously take place, without exceeding, however, the speed of 5 metres per second, which is .just the speed allowing a landing without accident, providing of course, that .the landing device is suitably. arranged.

The upper limit described previously, cannot be surpassedto a very great extent, as then the efficiencyofthezmachine would be reduced to such .extentzas to-be without'any interest. Obviously, :the'aerial navigation machine deprivedof itsengine has-no other way than to land within a' more or; less limited space of time, especially when the balloonin question is a flexible one.

.Let us consider the different cases by taking for example-an aerial navigation machine carrying 500.kilosof fuel, the total weight of which, without comprising the fuel, that is to1say,*envelope,

gas, passengers, engine, armament etc.,' being equal .to 1000 kilos.

nwhendescending vertically at the speed of 5 metres per. second. let us presume that the resistance opposed by the aerial navigation-machine is equalto 250 kilos. Thus fixing the resistance beforehand, for the same depends on the capacity of the envelope, it will enable us to deduce the volume therefrom and then determine the latter through successive approximations.

"This beingstated, the lower limit of the gross ascending force (that is to say, the lift of the air ,on the machine without any subtraction) should-be1000250 equal to 750 kilos, which corchine consists of an envelope 1,

responds to a volume of little more than 560 cubic metres, which is exceedingly reduced with regard to the comparatively big load of fuel provision, which is of 500 kilos.

At the start the machine is slightly heavier than the air, the surplus of weight being 250+500 (fuel) equal to 750 kilos.

- On the contrary, consider an ascending force equal to the upper limit fixed previously, that is to say, a gross ascending force (lift of the air -onthe machine without any subtraction) equal kilos, which corresponds to a volume of the envelope of little less than 1000 cubic metres.

' The machine carrying .its fuel is still slightly heavierthan the air, the excess of the weight at the start being of 250 kilos. But inthis third case, as soon as halfof the fuel is consumed, at

thisv moment the machine then becomes lighter than the air and'in case of failure'of the mechanism, will not drop.

However,'the fact should be noted, that the before-mentioned third case is not of great practical interest.

descent cannot be effected and especially, when multiple enginesare employed, permitting to con- 'tinue the "route by keeping only a small portion It should only be considered in the case of journeys above regions where the of the fuel and after having released the surplus of the fuel, in case of a total or partial failure of the engines.

' If the engines are of the multiple type it is advantageous to divide the tanks into as many compartments as there are engines, so that, if one of the engines fail definitely, the contents of only one of the compartments may be released.

Furthermore, if the stop of an engine can be consideredas temporary and is likely to be repaired, it will not be necessary to empty the corresponding tank immediately, but it will suffice to increase the action of the other engine or engines-during such time of the repair.

The auxiliary devices likely to increase the transversal-resistance of the envelope may be of any suitable type. Single collars surrounding the'envelope will be chosen, which, for instance, unfold at the moment of descent, whilst parachutesplaced on top of the envelope, which during the descent, will unfold equally as explained hereafter.

In the drawing: Fig. 1 shows a diagrammatic view of the whole aerial navigation machine.

Fig. 2 shows a diagrammatic detail of the use of-the auxiliar devices for braking of descent and Fig. 3 shows a rear view corresponding to Fig. 2.

Referring to Fig. l the aerial navigation maa chassis 2, a set of inclined sustaining propellers 3, propellers 4, of variable and reversible pitch working horizontally, tanks 5, which may be emptied instantaneously and even eventually be detached from the body of the aerial navigation machine; as shown they are disposed on the vertical of the centre of gravity G. 6 represents the sole engine and '7 the landing device. 8 represents the anchoring system with the harpoon projected by means of carbonic gas with its rope and the emptying device as described in the French patent specification filed by the same inventor on February 6th, 1930, (P. V. 289,514).

Figs. 2 and 3 show the arrangement of the collars around the envelope, as it is already known and applied to spherical balloons. Therefore, this arrangement is not claimed by the present invention and only given by way of example as to the means for increasing the transversal resistance to the descent.

A collar ab is arranged around the envelope and, due to the displacing of the machine, remains normally fiat against the said envelope, unfolding only during the descent. Such a collar attached to the envelope like a bandrol following the line 0, contributes to a great extent to increase the transversal resistance of the envelope. The ends of the bandrols ab are retained by small ropes (1, so that under the influence of the wind produced by the descent, the said bandrols, which surround the envelope, tend to unfold, without being capable of turning completely towards the top.

It should, however, be noted that it may be possible, due to the expansion of the envelope, to provide entirely opened parachutes on top of it, which may be separated from the envelope by the wind of descent.

Nevertheless, as, due to the backwind which follows the said envelope during its descent, the unfoldng of such parachutes covering, for instance, the upper surface of the envelope, presents certain difficulties, it is indispensable to make use of projection devices, which are to separate the parachute from the envelope. This will be easily attained by providing a tube f ending at the centre of the parachute and communicating with a gas tank 9, containing, for instance, carbonic acid under pressure.

When the gas enters the tube, the parachute will be inflated and is kept off sufficiently from the envelope, so that the wind on the descent may complete the unfolding at 6 (Figs. 2 and 3).

If the parachute covers the valve h, the same result is obtained by letting escape a certain quantity of gas through the valve, which will raise the parachute sufficiently so as to allow its removal from the envelope.

The retaining ropes of the parachute should normally terminate at a central fastening system 1', which in ordinary service maintains the parachute flat against the envelope and releases it only when necessary, in this case releasing the small ropes all at the same time.

This arrangement, which in itself is not fundamental, is only given by way of example for means which may be employed in order to increase the transversal resistance of the envelope and concerns the object of the invention only indirectly. In fact, many other arrangements may be realized and they only differ between themselves by their different efiiciency and their more or less difficult facility of use.

It is to be stated that the tanks should be mounted so as to be centred at the centre of gravity G or arranged in such a manner, so that their emptying does not unbalance the machine.

It does not matter what kind of rapidly working emptying device is employed. The simplest ones consist of a valve 9 with a big opening sustained by a belt, which can be operated at any moment by the pilot.

Obviously, it must be understood that the load so far described as fuel may be composed differently and include a certain part of non combustible materials destined only for projection.

This applies, for instance, to a water tank and artcles, which one can get rid of at any moment, such as uncharged bombs, instruments of no prime importance for the navigation, a wireless set, different impediments which one can easily release and which can be taken in account when calculating the weights at the start.

The machine must also be provided with a landing device representing on the ground a polygon of sustentation sufiicient to ensure the stability of the machine on the ground. Means of anchoring should be considered on the bow, thus to allow the landing on an open field and to avoid the dragging. It may be of some interest to utilize the means as mentioned in the Franch patent specification filed by the same inventor on the 6th February, 1930, Patent No. 705,665.

As explaned previously, the machine is slightly heavier than the air and therefore it must be provided with landing accommodations which are employed in such kind of aerial navigation machines.

If the whole machine does not differ substantially from a combined machine, it may be noted that the principle of the present invention consists of a determined combination of weights, transversal resistances of determined power and consequently of efforts of mechanical convenience as well as of the volume of the machine. All this permits to obtain with the same volume of gas provided a considerable increase of the speed of the machine and of its radius of action, ensuring at the same time sufiicient working safety.

What I claim is:

An aerial machine comprising an elongated envelope, a chassis depending therefrom, a propeller journaled to the rear end of the chassis for rotation about an axis parallel with the longitudinal ax s of the envelope, a second propeller journaled upon the chassis for rotation about an axis inclined upwardly toward the center of the envelope, the last said propeller and the axis thereof being located between the first mentioned propeller and a vertical plane passing through the envelope at a point midway between the ends thereof and a bandrol collar carried at the lower portion of the envelope and disposed over and spaced from the second mentioned propeller and adapted to receive a blast of air therefrom.

ETIENNE EDMOND OEHMICHEN. 

